<!doctype html>
<html>
<meta charset="utf-8" />
<script src="canvas2image.js"></script>
<style>
    .doc {
        width: 604px;
        margin: 0 auto;
    }
    canvas {
        display: block;
        border: 2px solid #888;
    }
</style>
<body>
<div class="doc">
    <canvas width="600" height="400" id="cvs"></canvas>
    <div>
        <p>
            <button id="save">save</button> or <button id="convert">convert to</button> as: 
            <select id="sel">
                <option value="png">png</option>
                <option value="jpeg">jpeg</option>
                <option value="bmp">bmp</option>
            </select><br/>
            width : <input type="number" value="300" id="imgW" /><br/>
            height : <input type="number" value="200" id="imgH" /><br>
            fileName: <input type="text" placeholder="optional" id="imgFileName">
        </p>

    </div>
    <div id="imgs">
        
    </div>
</div>
<script>
    var canvas, ctx, bMouseIsDown = false, iLastX, iLastY,
        $save, $imgs,
        $convert, $imgW, $imgH,
        $sel;
    function init () {
        canvas = document.getElementById('cvs');
        ctx = canvas.getContext('2d');
        $save = document.getElementById('save');
        $convert = document.getElementById('convert');
        $sel = document.getElementById('sel');
        $imgs = document.getElementById('imgs');
        $imgW = document.getElementById('imgW');
        $imgH = document.getElementById('imgH');
        $imgFileName =document.getElementById('imgFileName');
        bind();
        draw();
    }
    function bind () {
        canvas.onmousedown = function(e) {
            bMouseIsDown = true;
            iLastX = e.clientX - canvas.offsetLeft + (window.pageXOffset||document.body.scrollLeft||document.documentElement.scrollLeft);
            iLastY = e.clientY - canvas.offsetTop + (window.pageYOffset||document.body.scrollTop||document.documentElement.scrollTop);
        }
        canvas.onmouseup = function() {
            bMouseIsDown = false;
            iLastX = -1;
            iLastY = -1;
        }
        canvas.onmousemove = function(e) {
            if (bMouseIsDown) {
                var iX = e.clientX - canvas.offsetLeft + (window.pageXOffset||document.body.scrollLeft||document.documentElement.scrollLeft);
                var iY = e.clientY - canvas.offsetTop + (window.pageYOffset||document.body.scrollTop||document.documentElement.scrollTop);
                ctx.moveTo(iLastX, iLastY);
                ctx.lineTo(iX, iY);
                ctx.stroke();
                iLastX = iX;
                iLastY = iY;
            }
        };
        
        $save.onclick = function (e) {
            var type = $sel.value,
                w = $imgW.value,
                h = $imgH.value;
                f = $imgFileName.value;
            Canvas2Image.saveAsImage(canvas, w, h, type,f);
        }
        $convert.onclick = function (e) {
            var type = $sel.value,
                w = $imgW.value,
                h = $imgH.value;
            $imgs.appendChild(Canvas2Image.convertToImage(canvas, w, h, type))
        }
        
    }
    function draw () {
        ctx.fillStyle = '#ffffff';
        ctx.fillRect(0, 0, 600, 400);
        ctx.fillStyle = 'red';
        ctx.fillRect(100, 100, 50, 50);
    }
    
    
    onload = init;
</script>
</body>
</html>